0394246 JOHNSON DECAL SET

Using Fuel Consumption For Calculating the Overhaul Intervals
Experience has shown that maintenance intervals are most accurately based on fuel consumption. Fuel consumption corresponds more accurately to the engine load. Tables 1, and 2 list average ranges of fuel consumption and service hours for a load factor of approximately 25 percent.
Table 1
Maintenance Interval Schedule
Service Hours and Fuel Consumption for 3508C Locomotive Engines (1)    
    Rated 1301 to 1600 RPM     Rated 1601 to 1800 RPM    
Top End Overhaul     21600 Service Hours     18000 Service Hours    
971000 L (256510 US gal)
971000 L (256509 US gal)    
In-Frame Inspection     43200 Service Hours     36000 Service Hours    
1942000 L (513018 US gal)
1942000 L (513018 US gal)    
Second Top End Overhaul     64800 Service Hours     54000 Service Hours    
2913000 L (769530 US gal)
2913000 L (769530 US gal)    
Major Overhaul     86400 Service Hours     72000 Service Hours    
3884000 L (1026035 US gal)
3884000 L (1026035 US gal)    
( 1 ) Fuel consumption is based on a load factor of approximately 25 percent.
Table 2
Maintenance Interval Schedule
Service Hours and Fuel Consumption for 3512C Locomotive Engines (1)    
Interval Rated 1301 To 1600 RPM     Rated 1601 To 1800 RPM    
Top End Overhaul     21600 Service Hours     18000 Service Hours    
1460000 L (385690 US gal)
1460000 L (385690 US gal)    
In-Frame Inspection     43200 Service Hours     36000 Service Hours    
2920000 L (771375 US gal)
2920000 L (771375 US gal)    
Second Top End Overhaul     64800 Service Hours     54000 Service Hours    
4380000 L (1157065 US gal)
4380000 L (1157065 US gal)    
Major Overhaul     86400 Service Hours     72000 Service Hours    
5840000 L (1542750 US gal)
5840000 L (1542750 US gal)    
( 1 ) Fuel consumption is based on a load factor of approximately 25 percent.Use the actual records of fuel consumption, when possible. If the actual records are not available, use the following procedure in order to estimate the fuel consumption.
Estimate the average percent of the load for the operation of the engine.
Refer to the fuel consumption data in the Technical Marketing Information (TMI) for your engine. This will determine the fuel consumption for the percent of the load that was estimated in Step 1. Use this figure as variable "F" for the equation in Table 3. For more information about the Technical Marketing Information (TMI) for your engine, consult your Caterpillar dealer.
Table 3
Equation For Calculating Overhaul Intervals    
F/R = H    
"F" is the estimated total amount of fuel consumption of the engine.    
"R" is the rate of fuel consumption in liters per hour or gallons per hour.    
"H" is the number of estimated hours until the overhaul interval.    Oil Consumption as an Overhaul Indicator
Oil consumption, fuel consumption, and maintenance information can be used to estimate the total operating cost for your Caterpillar engine. Oil consumption can also be used to estimate the required capacity of a makeup oil tank that is suitable for the maintenance intervals.Oil consumption is in proportion to the percentage of the rated engine load. As the percentage of the engine load is increased, the amount of oil that is consumed per hour also increases.The oil consumption rate (brake specific oil consumption) is measured in grams per kW/h (lb per bhp). The brake specific oil consumption (BSOC) depends on the engine load. Consult your Caterpillar dealer for assistance in determining the typical oil consumption rate for your engine.When an engine's oil consumption has risen to three times the original oil consumption rate due to normal wear, an engine overhaul should be scheduled. There may be a corresponding increase in blowby and a slight increase in fuel consumption.